Australia have stumbled early in their Fed Cup semi-final with Germany after former US Open champion Sam Stosur lost to Andrea Petkovic in straight sets in Brisbane on Saturday.

Former world No.9 Petkovic blew away Stosur early before digging in to claim a 6-1 7-6 (9-7) victory in 101 minutes in the opening singles rubber at Pat Rafter Arena.

The pressure is now on Australian No.2 Casey Dellacqua to down world No.7 Angelique Kerber – ranked 46 places higher than her opponent – in Saturday’s other singles rubber.

Stosur had hoped to provide a dream start for Australia which are aiming to make their first Fed Cup final in 21 years and break a 40-year title drought.

Instead, she added to her dusty 2014 form.

Former world No.4 Stosur has only made it past the third round at one tournament this year and again appeared to buckle early under the weight of expectation on a home court.

A mountain of unforced errors by Stosur helped a fired up Petkovic break her opponent’s serve three times before snatching the first set in 38 minutes.

Stosur hit back, breaking Petkovic in the third game before moving to a 5-3 lead in the second.

Petkovic broke in the 10th game and forced a tie-break but needed her fourth match point to finally overcome Stosur.

It was a major blow for Australia which had relied on Stosur winning both her singles rubbers in their last encounter with Germany – an upset 3-2 triumph at Stuttgart two years ago.

Seven-time champions Australia were last crowned champions in 1974 with Evonne Goolagong leading the way.

Germany are in their first Fed Cup semi-final in 19 years.